Modular Synthesis of Conjugated Aromatic Boronate Esters by Radical Xanthate Addition

Conjugated aromatic boronate esters serve as crucial intermediates in the synthesis of pharmaceuticals and polymer materials. Traditional methods for their synthesis typically involve organoboration of aromatic ring compounds, where pre-constructions of aromatic rings are required. Here, we present a general strategy for the synthesis of diverse conjugated aromatic boronate esters based on the radical addition of xanthates. Through this method, we synthesized various boronate ester xanthates that could be utilized as a platform to furnish conjugated aromatic building blocks, including thiophenes, pyrroles, tetralones, naphthols, and naphthylamines. This cost-effective strategy holds promise as a viable method for the industrial-scale production of (hetero)aromatic boronate esters.